Keller W, König P, Richmond T J
Institut für Molekularbiologie und Biophysik, ETH-Hönggerberg, Zurich, Switzerland.
J Mol Biol. 1995 Dec 8;254(4):657-67. doi: 10.1006/jmbi.1995.0645.
The X-ray structure of the GCN4-bZIP protein bound to DNA containing the ATF/CREB recognition sequence has been refined at 2.2 A. The water-mediated interactions between the basic domain and DNA are revealed, and combined with a more accurate description of the direct contacts, further clarify how binding specificity is achieved. Water molecules extend the interactions of both invariant basic domain residues, asparagine 235 and arginine 243, beyond their direct base contacts. The slight bending of the basic domain alpha-helix around the DNA facilitates the linking of arginine 241, 243 and 245 to main-chain carbonyl oxygen atoms via water molecules, apparently stabilizing interactions with the DNA.
与含有ATF/CREB识别序列的DNA结合的GCN4-bZIP蛋白的X射线结构已在2.2埃分辨率下得到优化。揭示了碱性结构域与DNA之间由水介导的相互作用，并结合对直接接触的更精确描述，进一步阐明了如何实现结合特异性。水分子扩展了不变的碱性结构域残基天冬酰胺235和精氨酸243的相互作用，超出了它们与碱基的直接接触。碱性结构域α螺旋围绕DNA的轻微弯曲有助于精氨酸241、243和245通过水分子与主链羰基氧原子相连，显然稳定了与DNA的相互作用。
